Atopic dermatitis (AD) is a common inflammatory skin disease characterized by severe pruritus, a chronically relapsing course with frequent periods of exacerbation, a distinctive clinical morphology and distribution of skin lesions. Chronic AD may result in significant morbidity including hospitalization for control of skin disease and infection, school days lost, psychological trauma from physical disfigurement, occupational disability and the need for long term use of medications. The management of AD has been less than satisfactory and is directed toward symptomatic relief of symptoms or complications of this illness. J. M. Hanafin, J. Amer. Acad. Dermatol., 6: 1-13 (1982); D. Y. M. Leung et al., In: Dermatology and General Medicine, Fitzpatrick et al., (eds.), pp. 1385-1408, McGraw-Hill, Inc., New York (1986).
Although the primary cause of AD is unknown, substantial evidence suggests that excessive production of IgE directed to both food and inhalant allergens contributes to the pathogenesis of this disease. H. A. Sampson, J. Allergy Clin. Immunol., 81: 635-645 (1988); L. Tuft et al., J. Allergy, 23: 528-540 (1952). Recent studies have demonstrated that interferon gamma (IFN-.gamma.) suppresses in vivo and in vitro IgE synthesis in experimental animals, as well as IL-4 induced IgE synthesis in vitro by human peripheral blood mononuclear cells (PBMC). G. M. Snapper et al., Science, 236: 944-946 (1987); F. P. Heinzel et al., J. Exp. Med., 169: 59-72 (1989); R. L. Coffman et al., J. Immunol., 136: 949-954 (1986); F. D. Finkleman et al., J. Immunol., 140: 1022-1027 (1988). Patients with AD have been reported to have a number of T cell abnormalities including impaired supressor/cytotoxic T cell function and decreased capacity to produce IFN-.gamma. in response to a number of stimuli. D. Y. M. Leung et al., J. Immunol., 130: 1678-1682 (1983); D. Y. M. Leung et al., Clin. Rev. Allergy, 4: 67-86 (1986); U. Reinhold et al., Int. Arch. Allergy Appl. Immunol., 87: 120-126 (1988).
An effective treatment for chronic allergy-related disorders such as AD is needed.